They came back from a 4-0 deficit.

The world is going nuts over Barcelona's 6-1 win in its UEFA Champions League quarter final against Paris St Germain, completing a seemingly impossible comeback -- and why not?

Barcelona were 4-0 down after the first leg, and NOBODY comes back from that. Well, almost nobody. No team in club football -- and quite possibly no team in the history of club football -- has the across-the-ground strike power and class of Barca.

Having Neymar, Messi and Luis Suarez in the Barca line-up is a good start. But in this case it was not a Brazilian, Argentine or Uruguayan who did the damage, but fittingly at Barca's home ground, a Spaniard in the form of Sergi Roberto, who drilled home the winner deep in extra time.